山东济南和新泰馒头组中浊积岩和滑塌堆积的基本特征及其大地构造意义

FEATURES OF TURBIDITES AND OLISTOSTROME IN THE MANTOU FORMATION IN JINAN AND XINTAI, SHANDONG, AND ITS TECTONIC SIGNIFICANCE

馒头组是华北地台盖层的重要组成之一,以陆源细碎屑岩为主夹碳酸盐岩。前人研究认为馒头组是滨海沼泽相、潮坪—泻湖相和沿岸滩坝相沉积组合。我们首次在济南和新泰地区馒头组中发现浊积岩和滑塌堆积组合,表明华北地台早寒武世沉积组合形成于深海半深海浅海中,曾存在古斜坡和构造隆升作用。详细研究浊积岩和滑塌堆积的基本地质特征,不仅对于进一步认识华北地台古生代古地貌特征以及古潜山的形成和演化具有重要意义,而且可为渤海湾盆地中古潜山成因以及潜山油气资源勘探提供借鉴。

The Mantou Formation is one key strata on the North China craton, generally consisted of the finely terrigenous deposits dominantly with carbonate intercalations, which were interpreted as sediments of tidal flats and barrier island-lagoon complexes previously. The turbidities and olistostromes in the lower part of the formation were discovered firstly at Zhonggong commune, Jinan city, and Jiulongshan, Xintai city, indicating that the Early Cambrian deposits should occur in the pelagic to shallow sea, and an old slope and tectonic uplifting had ever existed in the North China craton. A study on geological characters of the turbidities and olistostromes in the formation must be important not only to recognize the Paleozoic palaeogeography of the North China, but also to provide some indictors for the mechanism of the buried hill and oil-gas exploration within these buried hills in and around the Bohai Bay Basin.